High speed data communication networks often use optical transceivers to transmit and receive optical signals carrying digitally encoded data. Optical transceivers typically use an optical transmitter, such as a laser, to transmit optical signals and an optical receiver, such as a photodiode, to receive optical signals. Conventional transceivers require a pair of optical fibers to implement full-duplex functionality. One optical fiber connects with the optical transmitter while the other optical fiber connects with the optical receiver.
Advancements in optical data communication technology have enabled bidirectional data transmission over a single optical fiber. These bidirectional communication systems can allow for data to be transmitted in both directions over a single optical fiber instead of requiring an individual optical fiber for each direction of data transmission. Bidirectional communication technology increases bandwidth by essentially doubling the data payload capacity. While bidirectional communication in optical networks can increase the amount of information that can be transmitted and received, these networks may still be affected by data transmission errors. Such errors can be caused, for example, by improper laser driver power control or modulation.
Diagnostic information is often used to address these types of problems. However, conventional diagnostic functions are open-loop in nature. For example, an optical transmitter can report its own output power and an optical receiver can report its own received optical power. While the optical transmitter or the optical receiver can provide useful diagnostic information, the diagnostic information may not be at the location best suited to utilize the information and implement a correction procedure because of the open-loop nature of the system. For example, an optical receiver that reports low optical power cannot be used by the optical transmitter that transmitted the optical signal. In other words, human intervention is typically needed to fix any problems indicated by the diagnostic information provided by the optical transmitter or the optical receiver. Further, conventional optical transceivers cannot self-compensate to maintain the integrity of the optical data when the data link degrades.